It will be appreciated that a Westinghouse Air Brake Company C-1 air dryer is designed so that it removes moisture vapor for the compressed air passing through it. In practice, the C-1 air dryer employs a single tower moisture removal, cleansing and regenerating system containing a desiccant material to absorb moisture from the air. That is, as the compressed air passes through the desiccant, the moisture is absorbed by the drying agent and retained until the compressor stops operating, and then dry, regenerative air passes back through the desiccant and picks up the collected moisture and discharges it to the atmosphere. Previously, the air drying function was performed by a preshaped stone-type cylinder of calcium chloride (CaC14) desiccant material. The pressed desiccant hollow cylinder was placed in the C-1 air dryer and was sealed on each end by a separate annular rubber gasket. While this preformed cylindrical block desiccant removed moisture from the compressed air, it had a number of shortcomings or disadvantages. First, the preshaped porous desiccant cylindrical block has a relatively small surface area so that it had a limited moisture-collection capability. Second, the desiccant block had a tendency to disintegrate into a fine grit while in service which could result in the contamination of the compressed air system. That is, the introduction of grit into the air stream could be detrimental and adversely affect the operation of various components of the air brake system. Third, the pressed desiccant material is relatively fragile and could not sustain rough handling and could only endure moderate compressive loads without breaking up into a number of separate pieces. Once the desiccant breaks up, its moisture-absorbing qualities are substantially impaired and are effectively destroyed.